Iron reacts with oxygen in the presence of moisture or water to form a red oxide called rust and the reaction involved is called as Redox reaction.

Hydroelectricity is electricity produced from hydropower i.e, water.

The one way how the progressives differed from populists is the populists are almost farmers whereas the progressives are typicaly middle class people who lives in the cities.

Here cellulose, sucrose and glycogen are all the forms of glucose. Hence, glucose includes all the other three given options.

Molecular compounds are those with covalent bonds between the elements and those elements are typically non metals.

Here in the given options, Ar is an element. NaI has an ionic bond. Hence, N2O4 has a covalent bond between the two non metals and is a molecular compound.

The correct statement among the given options about the process of scientific inquiry is "It is possible to test hypotheses, such as those involving historical events, without conducting experiments."

Although it is not possible to carry out experiments to test hypotheses about evolutionary relationships between living groups or about the timing of the origin of major evolutionary innovations, such hypotheses can be evaluated by making predictions about the expected findings that would result from these hypotheses. Data can then be collected to test whether these predictions are correct.

Enzymes are macromolecular biological catalysts. Enzymes accelerate chemical reactions. The molecules upon which enzymes may act are called substrates and the enzyme converts the substrates into different molecules known as products.